1. Field of Invention
The invention relates generally to means for measuring the level of liquid in a tank and particularly to a measuring stick type of gauge element wherein there is access to the gauge element from the exterior of the tank but the element itself is not exposed to the contents of the tank. Auxiliary means are provided to enable the operator to withdraw the gauge element to obtain a true indication of the liquid level. Gauge means embodying a tubular housing are mounted vertically in a tank with a movable gauge element therein and a float on the outside thereof together with means for orienting the gauge element vertically with reference to the float.
The invention is concerned with the provision of a flexible, extended measuring gauge element in the form of a band or tape like member having magnetic means at its remote end and mounted for vertical movement in an outer housing extending into a tank with the interior of the housing sealed off from the interior of the tank, in conjunction with a float on the outside of the housing carrying means for magnetically attracting the magnetic means of the gauge element.
2. Description of the Prior Art
It has been well known in the past to use solid, substantially rigid but lightweight rods which are either tubular, square or rectangular. Typical stick gauges are disclosed, for example in the patents to H. Nussbaum, U.S. Pat. Nos. 3,407,660 and 3,572,122, assigned to a predecessor in interest of the assignee of the present invention. Of additional interest is the patent to J. H. Field, et al, U.S. Pat. No. 2,949,776, also assigned to the predecessor in interest of the assignee herein.
Such rods have been made of fiberglass or other lightweight plastic materials. A problem with such substantially rigid gauge members of the prior art has been the fragility of such members. In the rough handling that is sometimes accorded the gauges, the rods have been known to break and therefore require replacement.
In addition, the task of imprinting or otherwise adding indicia to an extended circular, square or rectangular rod has required special and expensive printing processes. Because of the odd shape, the indicia have generally been added through expensive and time-consuming silk screen processes. Conventional high speed printing techniques which have obvious cost and speed advantages, have not generally been available.